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11.
Mohammad FK Alias AS Faris GA Al-Baggou BKh 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2007,54(3):140-143
A modified electrometric cholinesterase method has been described for use in ruminants exposed to organophosphate insecticides. The method was used to measure cholinesterase activities in the plasma and erythrocytes of sheep, goats and cattle treated with organophosphate insecticides under field conditions. The animals were treated topically to control ectoparasites with malathion (0.05%) or diazinon (0.06%). The treated animals did not suffer from adverse effects related to cholinesterase inhibition. However, 2 h after treatments, plasma and erythrocyte cholinesterase activities significantly decreased in sheep by 20% and 39% and in goats by 18% and 30%, respectively, when compared with respective untreated control values. Diazinon did not significantly affect plasma and erythrocyte cholinesterase activities in the cattle. The results suggest that the described electrometric method could be efficiently used for detecting cholinesterase inhibition in ruminants exposed to organophosphate insecticides. 相似文献
12.
Glutathione content of in vivo and in vitro matured canine oocytes collected from different reproductive stages 总被引:3,自引:0,他引:3
Kim MK Hossein MS Oh HJ Fibrianto HY Jang G Kim HJ Hong SG Park JE Kang SK Lee BC 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(6):627-632
Glutathione (GSH) concentrations of oocytes are considered as an important marker of the cytoplasmic maturation. The present study was designed to compare GSH concentrations of in vivo and in vitro matured canine oocytes. In vivo matured oocytes were collected 72 hr after ovulation by flushing fallopian tubes after laparotomy. Ovaries were collected from bitches with different reproductive stages, and collected oocytes were divided into 2 groups according to the size viz. < 120 microm and > 120 microm in diameter and cultured for 72 hr in Tissue Culture Medium-199 supplemented with 10% FBS, 2.2 mg/ml sodium bicarbonate, 2.0 microg/ml estrogen, 0.5 microg/ml FSH, 0.03 IU/ml hCG, and 1% penicillin-streptomycin solution in the presence or absence of 50 microM beta-mercaptoethanol. GSH concentrations were determined by the dithionitrobenzoic acid-glutathione disulfide (DTNB-GSSG) reductase recycling assay. GSH concentrations of immature canine oocytes were 2.9 and 3.8, 3.5 and 6.8, and 3.1 and 6.5 pM/oocyte for < 120 microm and > 120 microm in diameter oocyte groups at anestrous, follicular and luteal stage, respectively (P<0.05). In vivo matured oocytes had significantly higher GSH concentrations compared with in vitro matured oocytes. The GSH content was 19.2 pM/oocyte for in vivo matured oocytes, while 4.1 to 8.1 and 5.7 to 13.2 pM/oocyte for in vitro matured oocytes cultured in the absence or presence of beta-mercaptoethanol, respectively (P<0.05). Presence of beta-mercaptoethanol increased GSH synthesis in canine oocytes cultured in vitro, and oocytes collected from follicular and luteal stage was superior to anestrus oocytes. 相似文献
13.
14.
R. W. Skaggs M. A. Brevé A. T. Mohammad J. E. Parsons J. W. Gilliam 《Irrigation and Drainage Systems》1995,9(3):259-277
The design and management of drainage systems should consider impacts on drainage water quality and receiving streams, as well as on agricultural productivity. Two simulation models that are being developed to predict these impacts are briefly described. DRAINMOD-N uses hydrologic predictions by DRAINMOD, including daily soil water fluxes, in numerical solutions to the advective-dispersive-reactive (ADR) equation to describe movement and fate of NO3-N in shallow water table soils. DRAINMOD- CREAMS links DRAINMOD hydrology with submodels in CREAMS to predict effects of drainage treatment and controlled drainage losses of sediment and agricultural chemicals via surface runoff. The models were applied to analyze effects of drainage intensity on a Portsmouth sandy loam in eastern North Carolina. Depending on surface depressional storage, agricultural production objectives could be satisfied with drain spacings of 40 m or less. Predicted effects of drainage design and management on NO3-N losses were substantial. Increasing drain spacing from 20 m to 40 m reduced predicted NO3-N losses by over 45% for both good and poor surface drainage. Controlled drainage further decreases NO3-N losses. For example, predicted average annual NO3-N losses for a 30 m spacing were reduced 50% by controlled drainage. Splitting the application of nitrogen fertilizer, so that 100 kg/ha is applied at planting and 50 kg/ha is applied 37 days later, reduced average predicted NO3-N losses but by only 5 to 6%. This practice was more effective in years when heavy rainfall occurred directly after planting. In contrast to effects on NO3-N losses, reducing drainage intensity by increasing drain spacing or use of controlled drainage increased predicted losses of sediment and phosphorus (P). These losses were small for relatively flat conditions (0.2% slope), but may be large for even moderate slopes. For example, predicted sediment losses for a 2% slope exceeded 8000 kg/ha for a poorly drained condition (drain spacing of 100 m), but were reduced to 2100 kg/ha for a 20 m spacing. Agricultural production and water quality goals are sometimes in conflict. Our results indicate that simulation modeling can be used to examine the benefits of alternative designs and management strategies, from both production and environmental points-of-view. The utility of this methodology places additional emphasis on the need for field experiments to test the validity of the models over a range of soil, site and climatological conditions. 相似文献
15.
Rafeza BEGUM Mohammad M. R. JAHANGIR Mohammad JAHIRUDDIN Mohammad Rafiqul ISLAM Shaikh M. BOKHTIAR Khandakar R. ISLAM 《土壤圈》2022,32(6):916-927
Soil total organic carbon (TOC) is a composite indicator of soil quality with implications for crop production and the regulation of soil ecosystem services. Research reports on the dynamics of TOC as a consequence of soil management practices in subtropical climatic conditions, where microbial carbon(C) loss is high, are very limited. The objective of our study was to evaluate the impact of seven years of continuous tillage and residue management on soil TOC dynamics (quantitative and qualitati... 相似文献
16.
M. R. Pahlavan-Rad S. A. R. Movahedi-Naeini Mohammad Pessarakli 《Journal of plant nutrition》2013,36(6):874-888
The effects of irrigation water rates and seed bed shapes on changes in soil water and salinity status, bulk density, root growth and dry matter (DM) weights of wheat plants (Triticum aestivum L.) were investigated with a split plot design in a field trial in Zahak Agricultural Research Station in Sistan, Iran in 2005. Irrigation intervals after 80 and 160 mm evaporation from class A evaporation pan were used as main plot. Flat surface, single, triple, and six-row beds with a 20 cm row space were used as subplots. Each treatment was replicated four times. Volumetric soil water content and soil electrical conductivity (EC) were measured using Time Domain Reflectometry (TDR) at 0 —20, 20 —40 and 40 —60 cm depths at nine different times during the growing season. Soil water contents were also measured at 0 —10 and 10 —20 cm depths using standard sampling rings at four different times. The three and six-row beds increased the EC of the saturated paste extract with the more frequent irrigation intervals in this coarse textured soil. Soil water content, DM, and root density were always greater with the more frequent irrigations (shorter irrigation intervals). Root density was greatest in 0 —20 cm depth with the single row bed treatment. Grain yield and root density were greatest with single row bed treatment due to the bed shape at the root development stage (possibly due to a reduced mechanical resistance). A greater soil water content by the short irrigation interval increased grain yield and root density via reducing mechanical resistance. With the loamy sand, bulk density and mechanical resistance increased rapidly after cultivation. Bed shape at root development stage might have enhanced root growth and the crop yields. Apparently, mechanical resistance was the most limiting factor with these loamy sand soils than salinity. 相似文献
17.
The Penman–Monteith (FAO-56 PM) equation is suggested as the standard method for estimating evapotranspiration (ET0) by the International Irrigation and Drainage Committee and Food and Agriculture Organization (FAO). On the other hand, the Hargreaves–Samani (HS) equation is an alternative method compared with the FAO-56 PM equation. In the present study, the original coefficient C of the HS equation is calibrated based on the FAO-56 PM equation for estimating the reference ET0 from 15 meteorological stations in central Iran (about 170,000 km2) under semiarid and arid conditions. After calibration, the new values for C are ranged from 0.0018 to 0.0037. The mean bias error (MBE), the root mean square error (RMSE), and the ratio of average estimations of ET0 (R) values for all stations are ranged from 0.12 to 5.38, ?5.35 to 1.15 mm d?1 and 0.64 to 1.28 for the HS equation and from 0.12 to 2.48, ?2.2 to 0.60 mm d?1, and 1.00 to 1.05 for the calibrated Hargreaves–Samani equation (CHS), respectively. Results indicate that the average RMSE and MBE values are decreased by 40% and 66%, respectively. Relationships for calibrating the C coefficient on the basis of annual average of daily temperature range (ΔT) and wind speed (V) are proposed, calibrated, and validated. Hence, the CHS equation can be used for ET0 estimates with acceptable accuracy instead of the FAO-56 PM method. 相似文献
18.
Hanyeh Sepahvand Reza Mirzaeitalarposhti Torsten Müller 《Archives of Agronomy and Soil Science》2013,59(13):1820-1830
ABSTRACTThe aim of this study was to examine the usefulness of physical and chemical fractionation in quantifying soil organic matter (SOM) in different stabilized fraction pools. Soil samples from three land use types in Lorestan province, Southwest Iran were examined to account for the amount of organic carbon and nitrogen in different SOM fractions. Size/density separation and chemical oxidation methods were applied to separate the SOM fractions including particulate organic matter (POM), Si + C (silt and clay), DOC (dissolved organic C), rSOM (oxidation-resistant organic carbon and nitrogen) and S + SA (sand and stable aggregates). The values obtained for TOC, TN, and HWC were highest in forest lands followed by the range and agricultural lands. Among the SOM fractions, S + SA showed the highest values (5.75, 5.77 and 20.6 g kg?1 for agriculture, range and forest lands respectively) followed by POM, Si + C, rSOM, and DOC. The concentrations of C and N in the labile fractions obtained the higher values than in the stabilized fractions. Forest lands had the highest amounts of organic C and N among all fractions whereas agricultural lands showed highest values for inorganic C content of soils in different fractions. 相似文献
19.
Mohammad Noor Hossain Miah Tetsushi Yoshida Yoshinori Yamamoto 《Soil Science and Plant Nutrition》2013,59(1):205-217
Abstract A water culture pot experiment was conducted to analyze the effects of N application during the ripening period (RP) on photosynthesis, dry matter production, and its impact on grain ripening and yield in two semidwarf indica type varieties viz. Gui Zhao 2 (GZ) and BR3 (BR) compared with a japonica type variety Koganemasari (KO) under four N rates viz. 0 (N0), 10 (N10), 20 (N20), and 40 (N40) mg L?1. Results showed that N application enabled to maintain a higher leaf area and delay leaf senescence in both indica and japonica type varieties but the decrease in the rate, of leaf area was higher in the former than in the latter and the rate was reduced with increasing N rates. Flag leaf photosynthesis and SPAD values of N treated plants were higher throughout the RP, showing the presence of a significant correlation either for each variety or all the varieties together. Higher photosynthetic rate was supported by higher leaf chlorophyll (SPAD value basis) content, stomatai conductance, and N concentration in leaf blades. Top dry matter content increased with increasing N rates mainly due to mean leaf area rather than NAR except for BR during RP but it was higher in KO than in GZ and BR. Reduction of shoot weight due to translocation of dry matter to panicles during RP was suppressed by N rates both in GZ and BR while shoot weight increased in the N-treated plants in KO. The dependency of KO on current photosynthates for panicle weight was found to be almost hundred percent while the contribution of stored carbohydrates in shoot before heading to panicle weight in GZ and BR was in the range of 4-27 and 33-54%, respectively and the rest was contributed by current photosynthates. The percentage increased with increasing N rates. Percentage of ripened grains (PRG) increased with increasing N rates in GZ and BR due to the increase in dry matter production and in the photosynthetic rates of apex leaves, despite the larger spikelet number and larger hull size. However, KO showed almost no variation although it had the highest PRG among the varieties. Brown rice yield followed the same pattern as that of PRG in GZ and BR and the highest yield was produced by BR followed by GZ and KO. These results suggest that N application during RP was more effective in increasing yield in the semidwarf indica type varieties than in the japonica type variety. 相似文献
20.
Rahul Tripathi A. K. Nayak R. Raja Mohammad Shahid S. Mohanty B. Lal 《Communications in Soil Science and Plant Analysis》2017,48(10):1154-1166
Proper doses of nitrogenous fertilizer are most important for rice production system because a large part of the nitrogen may be lost if it is not applied judiciously. A study was conducted covering five blocks of Balasore and two blocks of Bhadrak districts. Soil samples were collected randomly, and field visit was conducted during peak vegetative stage of rice. Two approaches have been used in this study for estimating the site-specific nitrogen (N) requirement in the study area. In one approach, geostatisical analysis and kriging was used to develop the soil test–based N recommendation map by which a minimum of 72 kg N ha?1 and maximum of 94 kg N ha?1 were recommended. In a second approach, remote sensing was used and N recommendation map was developed using the moderate-resolution imaging spectroradiometer (MODIS) leaf area index (LAI) and normalized difference vegetation index (NDVI) satellite data, and a minimum requirement of 60 kg N ha?1 and maximum of 120 kg N ha?1 was estimated through this approach. 相似文献